Typically, to provide gas quality information related to a gas mixture, the speciation of the individual hydrocarbon species of the gas mixture is performed. After speciation of the individual hydrocarbon species, various combustion properties of the gas mixture may be calculated based on the individual components of the gas mixture. The calculated combustion properties may then be utilized to adjust various operational characteristics of an engine that combusts the gas mixture. Approaches to speciation of a gas mixture include the application of Fourier Transform Infrared Spectroscopy, Gas Chromatography, and Raman scattering-based techniques.